Summary of Work: The BLSA program in pulmonary aging is currently investigating the effect of body composition on pulmonary function and the risk of developing chronic obstructive lung disease. A. We completed a study that explored the effect of body fat distribution, as measured by waist-to-hip ratio (WHR), on pulmonary function. In this study, we combined spirometric and anthropometric measurements from 1094 men and 540 women (18 - 102 yr) in the BLSA to examine the effect of WHR on forced expiratory volume in 1 second (FEV1). Cross-sectional analyses, after accounting for body mass index (BMI) and other variables, showed a strong inverse association of WHR with FEV1 in men (&beta;= -1.338, p=0.0001) but not in women. Similar analysis of a subset of the above subjects (935 men and 439 women), showed that larger values of WHR were correlated with greater reductions of forced vital capacity (FVC) in men ( &beta;= -1.383, p=0.0005) as compared to women (&beta;= -0.679, p=0.02).Thus, body fat distribution has independent effects on lung function which are more prominent in men than women. ( Harik-Khan R, Wise RA. Fleg JL. The Effect of Gender on the Relationship between Body Fat Distribution and Lung Function Journal of Clinical Epidemiology, in press).B. Another study examined the relationship between body mass index (BMI) and the risk of chronic obstructive lung disease in 466 men in the BLSA. At baseline, the participants ranged in age between 40 and 73 years and were free of pulmonary disease. Over a mean follow-up of 10 years 10.1 % of the men developed chronic obstructive lung disease. A Cox proportional hazard model showed that in men the risk of developing chronic obstructive lung disease decreased as baseline BMI increased even after adjusting for other risk factors including cigarette smoking, age, FEV1% predicted, abdominal obesity and educational status ( Risk Ratio for lightest BMI tertile relative to heaviest BMI tertile = 2.42, 95 %confidence interval 1.09 - 5.3 ). The manuscript is being revised and will soon be submitted for publication.C. We are also studying the effects of socioeconomic status (SES), race and ethnicity on pulmonary function, using data from NHANES III. The latter survey has extensive, high quality information on a random sample of the U.S. population with an oversampling of African-American and Mexican-American populations. It is well established that African-Americans have lower levels of lung function than Caucasians, but it is not clear whether this is the result of differences in anthropometric measurements, physiologic characteristics or socioeconomic status. This is a particularly important issue for establishing normative values of lung function for clinical and medical-legal purposes. Progress to date: Dr. Harik-Khan has acquired full data set, extracted variables of interest, and attended workshop sponsored by the National Center for Health Statistics on NHANES III data sets.